Metal treating apparatus



Dec. 24, 1946. K. J. YOST METAL TREATING APPARATUS Filed Dec. 9, 1944QQmu S r Q INVENTOR.

KENNETH J YosT AGENT Patented Dec. 24, 1946 UNITED STATES PATENT OFFICE2,413,094 amma APPARATUS Kenneth; .LYojs't; westportflfionrig asfsignorto Remington Arms Qompan'yg hia', Bridgeport, Conn, a corporation ofDelaware Application December 9, 1944, swarm. 565,35

. 7 1 1 The present invention'relates to a device for treating articlesand is particlarly adaptedior pickling and washing metallic articlessuch as small arms ammunition components.

An object of the invention'is the provision of an improved drumfortreating' metal articles. A further objectis to provide a drum forpickling, washing or otherwise treating metal cups, draw pieces orcartridge cases, the drum being designed to enhance the freeand uniformrate'of movement of the articles therethrough. I

These and other objects features and advantages of the invention will bedescribed more fully in the following description of thei'inve'n tion,aneinbodiment'thereof being shown in the drawing, in which:

Fig, 1 is a side elevation, partly in section, of

the improved drum of this invention' including fragmentary portions ofsimilar drums secured at opposite ends thereof. v g

Fig.2 is a fragmentary plan view of the inside wall of the drumincluding a portion of the helix.

In general, cartridge cases are manufactured by punching and drawingbrass blanks from sheet stock. In the drawing or working of the brass,the metal work hardens and the resistance to fu'rther working or drawingincreases. can sequently, it is customary to anneal the drawn articlesor components between successive draws to restore the normal propertiesof the metal. The anneal is carried out in a suitable furnace throughwhich the articles are conveyed in quantity, surface oxidationinevitably occurring adjacent the furnace exit. The oxide or scale mustbe removed before the components are passed on to the next operation,and this is generally done by conveying the components through a dilutesolution of sulphuric acid, known as a pickling bath, after which thecomponents are rinsed and then neutralized or lubricated by immersion ina soap solution.

Apparatus for conveying the annealed components through the pickling,rinsing and lubricating baths has comprised, heretofore, a series ofperforated cones or drums arranged to rotate in tandem, that is to say,all turning together on a common longitudinal substantially horizontalaxis, the large or entrance end of each cone, with the exception of thefirst cone, being securely fastened to the small delivery end of thepreceding cone as indicated in Fig. 1. Each cone is adapted to besupported by rollers over a receptacle (not shown) containing or adaptedto contain an appropriate bath liquid, the relationship between eachcone and its bath being such that 2' only a limitedpor'tion of the lowerside of' each cone is immersed inthe bath, as indicated by the liquidlevel line in Fig. 1. A- spiral flange is formed on'the inner wall ofeach cone and provides a channel or passage for the components by whichthey are advanced from the forward end of the cone through the liquidbath and discharged from the rear end o-fthe cone int'oth'e forward endof the next succeeding cone. It has been customary to deliver theannealed compo-f nents'directly' from the furnace into the entranceendof the first cone, the latter being the pickling: drum. The'picklingdrum' conveys the componenfts through a dilute'sol'ution of sulphuricacid, and from thence to the next succeeding pair of: cones which conveythecornponents through a rinsing bath. From the rinse, the componentsare conveyed into the last cone where the compo: nents are immersed in asoap solution to further neutralize any acid thereon and to provide athin" lubricating coating on each component. 7

The foregoing description is simply for the purpose of teaching aproposed use of the iniproveddrum of thisinvention. A more detaileddescription of apparatus for similar purposes may be found in the priorart,as,' for example, the Needha'm patent, No, 1,383,413, July 5, 1921;

It will'be. understood, however, that the suggested use of the improveddruinfof this nventiori isnot a limitation thereof and that it mayhave'oth er uses and embody modifications all within the scope of theappended claims.

The drum shown in Fig. 1 comprises a substantially symmetrical conicalmember 10 having a relatively large entrance end II and a small exit ordelivery end l2, both the entrance end II and exit end I2 being shownbolted to the adjacent ends of similar cones. The shell or wall II) ofthe drum is perforated for a portion of its length and is provided onits inside with a continuous spiral flange or helix l3 formed integralwith the wall l0, the successive convolutions of the helix beingsubstantially equally spaced throughout the length of the cone.

In the present embodiment, the pitch p of the helix is substantially sixand one-half inches which has been found to be especially suitable forenhancin the freedom of movement of the components through the passageor channel l4 formed between successive convolutions of the helix.

As shown in the drawing, the first convolution l3 of the helix is notcomplete but extends substantially half way around the inside of thedrum and is spaced from the wall ID at the entrance end ll of the drum,a distance which is not less than the width 11 of the channel M. Inaccordance with this construction, the width of the helix channel [4 issubstantially uniform throughout its entire length and hence thepossibility of components being jammed between the wall of the drum andthe first convolution l3 of the spiral at the entrance end of the drumis preeluded.

The drum I0 is also provided with means to prevent articles frombecoming jammed or wedged in the channel M of the helix as they areadvanced therethrough. To this end an annular rib I5 is formed on theinner wall'of the drum substantially midway of each pair of convoluitions of the channel [4. As shown, the rib I5 is continuous in lengthand has a smoothly rounded profile IS. The ri-b I5 is of such heightthat I components disposed thereon will be held up off of and make anangle with respect to the bottom of the channel l4. As a consequence, itis impossible for two components to nest end to end, see Figs. 1 and 2,and hence to become wedged crosswise between the convolutions of thespiral. Moreover, those components which lie rosswise of the channelmake substantially point contact at their opposite ends with the rib l5and the bottom of the channel I4 respectively or with the rib and theadjacent flange or convolution of the spiral as shown in Fig. 1. Thecomponents are thereby supported in a comparatively unstable condition,and hence are susceptible to greater agitation, more thorough tumblingand more rapid advancement through the drum than has been the case whenthe components were allowed to lie fiat and become jammed on the bottomof the channel. Fig. 1 also illustrates one component lying with itslongitudinal axis substantially parallel to the longitudinal axis of thechannel and a second component extending transversely of the channel andsupported precariously on the rib l5. Again there is no possibility ofcomponets so disposed becoming wedged between the parallel flanges ofthe spiral. The width of the channel l4 isdetermined in part by thegeometry of the components and is such that, in the event two componentsextending longitudinally in the channel substantially side by side, asshown in Fig. 2, the component adjacent the center of the channel willcontact the relatively large radius r at well known means such asdescribed in the aforementioned patent, and hence all components in thedrum will be advanced freely and at a substantially uniform rate throughthe drum. The

1 improved performance of the drum is especially manifest when suchrequirements as critical 1m- 'mersion periods and quantity productionschedules are to be achieved.

What is claimed is:

1. A device for conveying articles through a bath comprising a conicalperforated drum rotatable on its longitudinal axis in a substantiallyhorizontal plane, said drum having a spiral internal flange by whicharticles deposited in said drum are gradually advanced therethrough; andan annular rib on the inner wall of said drum, said rib being arrangedparallel to and intermediate successive convolutions of said spiral toprevent articles from wedging therebetween.

' 2. In a device for conveying articles through a bath, the combinationwith a conical perforated drum rotatable on its longitudinal axis in asubstantially horizontal plane and having an entrance end; of a spiralinternal flange in said drum, said spiral comprising substantiallyequally spaced convolutions arranged to gradually advance articlesthrough said drum, and an incomplete convolution'at the entrance end ofsaid drum arranged to provide a space between the beginning of saidspiral and the adjacent wall of said drum of a width' not less than thedistance between successive convolutions of said spiral to preventarticles from jamming at the entrance end of said drum; and an annularrib on the inner wall of said drum, said rib being arranged parallel toand midway of successive convolutions of said spiral to prevent articlesfrom wedging between successive convolutions of said spiral. v KENNETHJ. YOST.

